@article{10_4064_ap_45_3_237_243,
     author = {Marek Ptak},
     title = {Unitary dilations of multi-parameter semigroups of operators},
     journal = {Annales Polonici Mathematici},
     pages = {237--243},
     publisher = {mathdoc},
     volume = {45},
     number = {3},
     year = {1985},
     doi = {10.4064/ap-45-3-237-243},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/ap-45-3-237-243/}
}